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N0 Model.)

J. H.,BROWN. MANUFACTURE 01- GUNS.

NO. 496,395. Patented May- 2,1893." ||||m UNITED STATES PATENT OFFICE.

JOHN H; BROWN, OF NEW YORK, N Y.

MANUFACTURE ensure s.

SPECIFICATION forming part of Letters Patent No. 493,395, dated May 2, 1893.

T Application filed September 17. 1890. Renewed June 3, 1891- .Again renewed February 6, 1892, and again renewed August 26' 1892. Serial No. 444.173. (No model.)

To aZl whom it may concern.-

Be it known that I, JOHN H. BROWN, of the city and county of New York, in the State of New York, have invented a new and useful Improvement in the Manufacture of Guns, of

which the following is a specification.

My invention relates to an improvement in the manufacture of guns.

In modern guns, the system adopted to resist the bursting action of powder is that known as the system of initial-tension. That is, the core of the gun is placed under a condition of initial tension (compression) by the application of exterior jackets or hoops of i 5 solid metal or by winding the core with wire under tension. The initial compression thus produced is a maximum at the surface of the bore of the gun; and this maximum compression must be overcome by the powder :0. pressure before the core can be stretched beyond its elastic limit. It is therefore evident that if this maximum'initial tension or compression be so great at the surface otthe bore that it cannot be overcome by powder press- A ure, the metal of the core wlllnotbe stretched beyond its elastic limit, as the entire powder pressure will be expended in the effort to over come said initial tension or compression.

In modern rifled guns the important object is to obtain such a condition of initial compression at the surface of the bore that the radial or bursting stress due to the explosion of gun powderwill not exceed either the clastic limit of extension or compression of the metal, so as not to permanently enlarge the bore and thus destroy the accuracy of the gun. It is further evident that if the initial compression is so great that it cannot be overcome by powder pressure, the metal surrounding the bore cannot be extended either beyond its elastic limit for compression or extension unless the initial tension itself be sufficient to overcome such elastic limit.

It isarecognized principle of the art of gun construction that the elastic limit of compression must not be exceeded in applying the initial tension; and, as the natural elastic limit of steel is not sufiicient to admit of a compression at the surface of the bore so 50 great that it cannot be overcome by powder pressure, it is necessary to resort to some method-of setting up a condition of special elasticity in the metal of the core in order to construct a core capable of receiving such high pressure.-

The primary object of my present invention is to construct a core of a gun capable of receiving the highest conditions of special elasticity, and therefore capable of supporting. an initial tension at the surface of the bore 66 so great that it cannot be overcome by the pressure of the explosive charge, namely, between sixteen andeighteen long tons per square inch, in thecase of gun powder.

A further object is to construct a gun in. which the-core shallbe subjected to an initial tension greater than that of the bursting stress of the charge.

VVith' these ends in view myinvention con- 'sists in forming the core of the gun in longi- 7o tudinal segments and subsequently setting up in each of the 'core'segmeuts a condition of special elasticity for the reception of the necessary initial tension.

My invention further consists in forminga gun by first forming the core in longitudinal segments, then setting up in each of the core segments a condition of special elasticity and then submitting the assembled core segments to an initial tension sufiicientlygreat to with: stand the explosive stress of the charge.

- In the accompanying drawings, Figure 1 represents a vertical longitudinal section of a gun constructed in accordance with my improved method. Fig. 2 is an enlarged trans: verse section of the same through lines: to of Fig. 1. Fig. 3 represents a view of the core in side elevation, and, Fig. 4. represents an enlarged transverse section of the same through line '3 y of Fig. 2. Y t

A represents one of the series of longitudi-. nal core segments which when assembled form the complete core of the gun. The opposite sides of each segment gradually approach each other from the outerto the inner edge 5 in conformity with radial lines drawn from the longitudinal axis of the gun and the said segments "gradually decrease in depth from the breech to the muzzle of the gun. The surrounding jacket, by means of which the we required initial tension is given to the core is represented by B and is here shown as formed ifs .ilO

the size and shape of the completed gun. The

condition of special elasticity may be set up in each of said sufficiently small longitudinal segments either by tempering and an nealing, cold rolling, cold drawing,.or any other method known to science capable of inducing it. After the core segments have been shaped and manipulated so as to set up within them the special elasticity referred to, they are assembled by means of nuts, bands, hoops or other similar devices into a core of a gun ready to receive the superimposed jacket for producing the initial tension before referred to. Such initial tension is applied by winding the core with wire under a high degree of tension. In the present. instance the degree hf tension used in winding is such as to produce at the surface of the boron. degree of compression so-great that it will not be overcome by the powder pressures used in modern guns. This willbeacompression of about forty tons P81 square inch at the surface of the bore.

It is a well known fact by all authorities that an elastic limit may be set up in pieces of steel of small dimensions amounting to forty tons per square inch. The elastic limit not good steel wire is double this amount. Therefore, a segmental core made of such steel maybe placed under a condition of initial compression at the surface of the bore of forty tons per square inch without liability of exueeding the elastic limit of compression in the metal. The amount of internal pressure required to overcome this tension or compres sion may be determined by Birnies formula. For example, take thecase of a cylinder having a bore of ten inches, the thickness of metal being ten inches the-initial compression at the surface of the bore forty tonsper square inch, then,

900+5O This is far above ordinary powder pressure which rarely exceeds eighteen tons per square inch. The wire thus wound may be guarded against injury by means of an outer steel jacket and any well known or approved form of breech mechanism may be used. In the form of gun which I have represented in the accompanying drawings to illustrate the present invention, the trunnions are attached to 252 tons per square inch.

the outer jacket of ,steel, which is attached to the gun at the breech nutonly, the gun being free to expand longitudinally through the jacket whereby the thrust of recoil is transmitted directly to the carriage by means of the breech nut, jacket and trunuions.

What I claim as my invention is- 1. In gun construction, first forming the core of the gun in longitudinal segments and subsequently setting up in each of the core segments a condition of special elasticity by cold rolling or other suitable means for tempering, substantially as and for the purpose set forth.

2. In gun construction, first forming the core in longitudinal segments, then setting up in each of the core segments a condition of special elasticity by suitable tempering and subsequently assembling the core segments and submitting the assembled-segments or core to an initial tension sufiiciently great to stand the explosive strain of the charge by means of jacketing, substantially as set forth.

JOHN 1-1. BROWN. 

